Urinary drainage bags are frequently used in hospitals to collect urine from patients over considerable lengths of time. Typically, a urethral catheter is inserted in the patient and the catheter connected to a urinary drain tube which leads to a collection bag attached to the bed rail or the like. These bags are periodically emptied, and every effort is made to prevent any bacterial contamination that might grow in the collected urine from migrating back to the patient's bladder, causing a urethral or bladder infection.
In recent years, it has been the practice to include drip housings, valves, and other air breaks in the line between the patient and the collection bag. Because the urine collection bags are disposed of after a single patient use, they must be made very inexpensively and very reliable relative to leakage.
One type of urine bag construction has included two flap flexible panels sealed together about their peripheries with tubular inlet and outlet ports sealed between the two superimposed panels (U.S. Pat. No. 3,415,299) or sealed to a side wall of the bag (U.S. Pat. No. 3,568,965). The former patent has a practical drawback in that it is difficult to reliably seal two flat sheets around a tubular neck. Sealing inlet and outlet ports to a bag side wall often requires expensive elbow connections and such connections to a highly flexible bag wall are difficult to control as the bag is moved about.
In a different field of blood collection and dispensing bags, it has been proposed to use a "folded" top structure with a stiffening saddle carrying the port structure to the bag's top (U.S. Pat. No. 3,509,879). Here the blood bag was supported on a wire hook of a separate I.V. stand which hooked into a flexible extension of the bag wall itself. There was no hanger structure mounted on the rigidifying saddle which was the firmest and most easily controllable part of the blood bag. Handling a filled blood bag is somewhat similar to handling a water-filled balloon. However, this did not pose a significant problem in blood bags which are of approximately one pint capacity. Handling a sloppy urine collection bag of 2,000 ml capacity (approximately 1/2 gal.) or more is more difficult without a firm handle control. Skewer type wire hangers (U.S. Pat. No. 3,090,968) lack the firm control and support for the bag.
It is desirable to vent the flexible bag (U.S. Pat. No. 3,568,965) with a hydrophobic vent. However, when the vent is in imminent contact with an opposing wall of the bag, sometimes urine can collect for long periods of time at the vent area with the two walls having a somewhat capillary action in holding the urine. This might happen if the bag were temporarily tilted to barely wet the filter. A wet filter over long periods of time could become clogged with urinary salts which could substantially reduce its venting and filtering efficiency. This is much less likely to happen where the bag wall filter is based a substantial distance from its opposing wall. Also, bag walls that are held in separated condition in an area of the liquid inlet help reduce the chance of retrograde bacterial growth even though with tilting and flexing of the bag during use a limited area of the bag's inlet structure could come in contact with one or both of the bag's side walls.